DAM Decrease without any knock?
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This is a discussion on DAM Decrease without any knock? within the Tuning: Electronic Engine Management forums, part of the Tech & Modifying & General Repairs category; After about 6 months of driving my 2012 STI in it's stock form I finally flashed a cobb stage 1 ...

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    Registered User Dramlin's Avatar
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    DAM Decrease without any knock?

    After about 6 months of driving my 2012 STI in it's stock form I finally flashed a cobb stage 1 map this weekend (91 -stock air filter, stage 1). After flashing I immediately went out for 2 quick datalogs in 4th gear, going from ~3000rm to 6000rpm. Everything looks good as far as I can determine, however on my first log I noticed my DAM decreased from 1 to .88 @5400rpm. What's puzzling me is ther both of my logs show that there was no feeback knock and very little fine learning knock (.29 in a few area's - nowhere near where the DAM decrease occurred). About 1.5 driving hours later my DAM is sitting at .94

    Does anyone know why the DAM would suddenly decrease when there is no knock detected? I read up on the DAM information on Cobb's website, but it didn't seem to provide any answers. I can post the datalogs if it helps.

    thanks in advance
    2012 PBP Limited STI
    2002 Aspen White WRX Wagon, Stage 1

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    Subaru Newb MainFrame's Avatar
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    Drive the car some more, then log it again and see if it continues to happen..

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    Master Baiter EJ257's Avatar
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    2005 WRX STi (Mods | Virtual Dyno)

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    Registered User teflon_jones's Avatar
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    Doing a log right after a flash is pointless. You have to let the ECU learn the tune. Throw away those results and forget about them.
    Scott
    Past Subies - '11 STI Limited stage 1+ and '04 STi stage 2+
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    Registered User Dramlin's Avatar
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    Thank you all for your sage advice, especially EJ257 for the reading material.

    After reading over how the ECU manages IAM/DAM adjustments, I'm still puzzled as the criteria should not have been met to reduce the IAM/DAM. Overall it doesn't matter though, as you are all correct in that it is too early to jump to conclusions. I will continue to log and just watch it for awhile.

    Last question-- after a flash about how long should you wait before you can get an accurate datalog (2 fill ups, xxx amount of miles, etc)? I understand that each car will be different, but I'm sure there is a general timeframe to where the ECU has learnt enough for the results to be valid
    2012 PBP Limited STI
    2002 Aspen White WRX Wagon, Stage 1

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    Registered User Ingo's Avatar
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    She has to go thru all the different driving conditions before you can be fairly sure to have all the "learning" done. That is some city, country and interstate driving. Nowhere is there an actual number for this. Just drive a bit of everything, 50 - 100 miles should be enough, I'd think.
    You can't have everything - where would you put it?

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    Master Baiter EJ257's Avatar
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    Quote Originally Posted by Dramlin
    Last question-- after a flash about how long should you wait before you can get an accurate datalog (2 fill ups, xxx amount of miles, etc)? I understand that each car will be different, but I'm sure there is a general timeframe to where the ECU has learnt enough for the results to be valid
    It depends on how the map is setup. A few miles should be enough to get the IAM/DAM up, if it's retarded by the "Initial IAM/DAM" value in the ECU.
    2005 WRX STi (Mods | Virtual Dyno)

    Resident Tuner @ WTF Tuning, LLC

    "Never trust anything that bleeds for a week and lives ..."

    UNYSOC

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